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Dive into the research topics where Matthias Walter is active.

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Featured researches published by Matthias Walter.


PLOS ONE | 2015

Do We Need Surveillance Urethro-Cystoscopy in Patients with Neurogenic Lower Urinary Tract Dysfunction?

Ulla Sammer; Matthias Walter; Stephanie Knüpfer; Ulrich Mehnert; Beata Bode-Lesniewska; Thomas M. Kessler

Purpose To examine the value of surveillance urethro-cystoscopy in patients with neurogenic lower urinary tract dysfunction (NLUTD) in regard to the conflicting literature as it is generally agreed that patients with NLUTD are at increased risk for bladder cancer. Materials and Methods In a cross-sectional study, a consecutive series of 129 patients (50 females, 79 males, mean age 51, range 18–88) suffering from NLUTD for at least 5 years was prospectively investigated using urethro-cystoscopy and bladder washing cytology at a single university spinal cord injury (SCI) center. Results Due to suspicious urethro-cystoscopy and/or bladder washing cytology findings, 13 (10%) of 129 patients underwent transurethral resection of the bladder lesion and/or random bladder biopsies. Overall, 9 relevant histological findings were found in 5% (7/129) of our patients: bladder melanosis (n = 1), nephrogenic adenoma (n = 3), keratinizing squamous metaplasia (n = 1), intestinal metaplasia (n = 3), and muscle-invasive adenocarcinoma of the bladder (n = 1). Conclusions Using surveillance urethro-cystoscopy, we found relevant histological findings in 5% of our patients suffering from NLUTD for at least 5 years. Thus, surveillance urethro-cystoscopy might be warranted, although the ideal starting point and frequency remain to be determined in further prospective studies.


Developmental Neurorehabilitation | 2014

Intrathecal baclofen therapy in children with severe spasticity: Outcome and complications

Matthias Walter; Stefan Altermatt; Claudia Furrer; Andreas Meyer-Heim

Abstract Objective: To investigate clinical efficacy and incidence of complications regarding intrathecal baclofen (ITB) therapy in children. Methods: Retrospective medical chart review of 15 paediatric patients with congenital brain injuries who underwent ITB implantation for treatment of severe spasticity between 2003 and 2009. Results: Compared to the preoperative state, ITB therapy significantly reduced spasticity of lower limbs with corresponding decrease of the modified Ashworth scale (p < 0.05), while baclofen dosage increased (p = 0.001). Cobb angle of patients with scoliosis prior to ITB therapy (n = 8) increased significantly (p < 0.05) during follow-up. Overall, 10 complications (nine device related and one accidental) were found in six patients (40%), mostly emerging within the first three years after implantation. Conclusion: Intrathecal baclofen is an effective therapy option for paediatric patients to significantly reduce spasticity of lower limbs. The high incidence of complications implicates the need for a close monitoring of the patients especially in the early post-operative period.


PLOS ONE | 2016

Urodynamic Investigation: A Valid Tool to Define Normal Lower Urinary Tract Function?

Lorenz Leitner; Matthias Walter; Ulla Sammer; Stephanie Knüpfer; Ulrich Mehnert; Thomas M. Kessler

Objectives To evaluate whether urodynamic investigation (UDI), the gold standard to assess refractory lower urinary tract symptoms (LUTS), is appropriate to select healthy volunteers with apparent normal lower urinary tract function as control subjects for comparative studies. Subjects and Methods 42 healthy subjects (22 women, mean age 32±10 years; 20 men, mean age 37±12 years) without LUTS were included into this prospective single-centre cohort study. All subjects recorded a 3-day bladder diary, completed validated questionnaires regarding LUTS, and underwent neuro-urological assessment as well as free uroflowmetry. Same session repeat UDI was performed according to “Good Urodynamic Practice” recommended by the International Continence Society, but using an air-charged instead of a water-filled catheter, and evaluated by a blinded investigator. Results All 3-day bladder diaries, LUTS questionnaires, neuro-urological assessments and free uroflowmetries were within normal limits. Overall (either during the first or second UDI), same session repeat UDI revealed pathological findings in 71% (30/42): Detrusor overactivity was detected in 14% (3/22) and 30% (6/20), post void residual >100mL in 14% (3/22) and 25% (5/20), bladder outlet obstruction in 9% (2/22) and 20% (4/20) and detrusor sphincter dyssynergia in 77% (17/22) and 65% (13/20) of our women and men, respectively. Repeatability of detrusor overactivity (κ = 0.78, 95% CI: 0.54–1.02) and detrusor sphincter dyssynergia (κ = 0.77, 95% CI: 0.55–0.98) showed substantial agreement between both UDIs. All other assessed urodynamic parameters had wide 95% limits of agreement for differences in the parameters indicating poor repeatability. Conclusions More than 70% of our healthy subjects showed pathological urodynamic findings. Although UDI is the gold standard to assess refractory LUTS, it seems not to be applicable in healthy subjects to define normal lower urinary tract function. Therefore, we do not recommend using UDI to select healthy control subjects.


BMJ Open | 2014

Protocol for a prospective neuroimaging study investigating the supraspinal control of lower urinary tract function in healthy controls and patients with non-neurogenic lower urinary tract symptoms

Matthias Walter; Lars Michels; Spyros Kollias; Philip Van Kerrebroeck; Thomas M. Kessler; Ulrich Mehnert

Introduction Lower urinary tract symptoms (LUTS) are highly prevalent, cause an enormous economic burden on healthcare systems and significantly impair the quality of life (QoL) of affected patients. The dependence of the LUT on complex central neuronal circuits makes it unique in comparison to other visceral functions, such as the gastrointestinal tract, but also more vulnerable to neurological diseases. Methods and analysis This is a prospective neuroimaging study investigating the supraspinal control of LUT function in healthy controls and in patients with non-neurogenic LUTS. The clinical assessment will include medical history, neuro-urological examination, bladder diary, urine analysis, urodynamic investigations, as well as standardised questionnaires regarding LUTS and QoL. The acquisition of neuroimaging data will include structural assessments (T1-weighted imaging and diffusion tensor imaging) as well as functional investigations using blood-oxygen-level dependent sensitive functional MRI (fMRI) in a 3 T MR scanner. The fMRI will be performed during four different bladder tasks using an automated MR-compatible and MR-synchronised pump system. The first three task-related fMRIs will consist of automated, repetitive filling of 100 mL warm (37°C) saline starting with (1) an empty bladder, (2) a low prefilled bladder volume (100 mL) and (3) a high prefilled bladder volume (persistent desire to void). The fourth task-related fMRI will comprise of automated, repetitive filling of 100 mL cold (4–8°C) saline starting with an empty bladder. Ethics and dissemination The local ethics committee approved this study (KEK-ZH-Nr. 2011–0346). The findings of the study will be published in peer-reviewed journals and presented at national and international scientific meetings. Trial registration number This study has been registered at clinicaltrials.gov (http://www.clinicaltrials.gov/ct2/show/NCT01768910).


Urologe A | 2012

Chronisches Schmerzsyndrom des Beckens

Matthias Walter; Ulla Sammer; Thomas M. Kessler

Chronic pelvic pain syndrome (CPPS) is defined by the European Association of Urology guidelines as a non-malignant pain perceived in structures related to the pelvis of either women or men for at least 6 months without proven infection or other obvious pathology. It affects the quality of life of millions of people worldwide and has an impact similar to that reported for other chronic diseases, such as diabetes mellitus, Crohns disease and congestive heart failure. The treatment of CPPS remains a challenge despite several established first line therapies because many patients are therapy refractory. Unconventional treatments, such as neurostimulation, neuromodulation and acupuncture may be highly successful for treating CPPS and have a favorable adverse event profile. Thus, these promising therapeutic alternatives should be considered more often in daily clinical practice.


Urologe A | 2012

[Chronic pelvic pain syndrome: neurostimulation, neuromodulation and acupuncture].

Matthias Walter; Ulla Sammer; Thomas M. Kessler

Chronic pelvic pain syndrome (CPPS) is defined by the European Association of Urology guidelines as a non-malignant pain perceived in structures related to the pelvis of either women or men for at least 6 months without proven infection or other obvious pathology. It affects the quality of life of millions of people worldwide and has an impact similar to that reported for other chronic diseases, such as diabetes mellitus, Crohns disease and congestive heart failure. The treatment of CPPS remains a challenge despite several established first line therapies because many patients are therapy refractory. Unconventional treatments, such as neurostimulation, neuromodulation and acupuncture may be highly successful for treating CPPS and have a favorable adverse event profile. Thus, these promising therapeutic alternatives should be considered more often in daily clinical practice.


BJUI | 2017

A novel infusion-drainage device to assess lower urinary tract function in neuro-imaging.

Lorenz Leitner; Matthias Walter; Behnaz Jarrahi; Johann Wanek; Jörg Diefenbacher; Lars Michels; Martina D. Liechti; Spyros Kollias; Thomas M. Kessler; Ulrich Mehnert

To evaluate the applicability and precision of a novel infusion‐drainage device (IDD) for standardized filling paradigms in neuro‐urology and functional magnetic resonance imaging (fMRI) studies of lower urinary tract (LUT) function/dysfunction.


Scientific Reports | 2016

Antibiotic prophylaxis may not be necessary in patients with asymptomatic bacteriuria undergoing intradetrusor onabotulinumtoxinA injections for neurogenic detrusor overactivity.

Lorenz Leitner; Ulla Sammer; Matthias Walter; Stephanie Knüpfer; Marc P. Schneider; Burkhardt Seifert; Jure Tornic; Ulrich Mehnert; Thomas M. Kessler

Many of the patients undergoing intradetrusor onabotulinumtoxinA injections for refractory neurogenic detrusor overactivity (NDO) present with chronic bacteriuria. In these patients, antibiotic prophylaxis has been widely recommended since bacteriuria might impair treatment efficacy and cause urinary tract infections (UTI) but the evidence is limited. The aim of this study was to evaluate if an antibiotic prophylaxis is needed in patients with asymptomatic bacteriuria undergoing intradetrusor onabotulinumtoxinA injections. Between 06/2012 and 12/2014, a consecutive series of 154 patients undergoing a total of 273 treatment cycles were prospectively evaluated. Before treatment urine samples were collected, patients with no clinical signs for UTI underwent onabotulinumtoxinA injections, no antibiotic prophylaxis was given. Asymptomatic bacteriuria was found in 73% (200/273 treatments). Following treatment, UTI occurred in 5% (9/200) and 7% (5/73) of patients with and without bacteriuria, respectively. Intradetrusor onabotulinumtoxinA injections were clinically and urodynamically successful in 70% (192/273). There was no association between bacteriuria and treatment-related adverse events (odds ratio 0.64, 95% CI 0.23–1.81, p = 0.4) nor between bacteriuria and therapy failure (odds ratio 0.78, 95% CI 0.43–1.43, p = 0.4). Thus, we conclude that antibiotic prophylaxis needs to be critically reconsidered in patients undergoing intradetrusor onabotulinumtoxinA injections, especially taking into account the alarming antibiotic resistance worldwide.


Brain Injury | 2015

Intrathecal baclofen therapy in children with acquired brain injuries after drowning: A case series

Matthias Walter; Stefan Altermatt; Claudia Furrer; Andreas Meyer-Heim

Abstract Objective: To investigate clinical efficacy as well as the incidence and extent of complications regarding intrathecal baclofen (ITB) therapy in children. Methods: This is a retrospective medical chart review of three paediatric patients with acquired brain injuries (ABI) resulting from drowning who underwent ITB pump implantation for treatment of severe spasticity. Results: Compared to the pre-operative state, ITB therapy reduced spasticity with a corresponding decrease of modified Ashworth scale in upper (3.2 ± 1.4 to 1.3 ± 0.6) and lower extremities (3.5 ± 0.9 to 2.0 ± 1.0). Overall, six complications, five device-related and one accidental, were found in two out of three patients. Conclusion: Intrathecal baclofen is an effective therapy option for paediatric patients with ABI after drowning to significantly reduce spasticity of upper and lower extremities. A word of caution must be addressed to the incidence and extent of complications related to ITB therapy.


The Journal of Urology | 2017

PD70-10 ABNORMAL RESTING-STATE INTER-NETWORK COUPLING IN PATIENTS WITH NON-NEUROGENIC OAB

Lorenz Leitner; Ulrich Mehnert; Matthias Walter; Thomas M. Kessler; Spyros Kollias; Lars Michels

INTRODUCTION AND OBJECTIVES: Recent fMRI studies using bladder filling tasks demonstrated alterations in supraspinal LUT control networks (NT) in women with OAB, particularly regarding NT connectivity and white matter changes. It is unclear if patients with OAB show altered supraspinal responses during empty bladder conditions and if resting-state (RS) activity is altered by catheterization usually require for bladder filling tasks. We applied a functionally-motivated NT approach, using RS functional NT connectivity (RS-FNC) analysis, to examine RS related NT interactions in age-matched controls and OAB patients. Based on previous publications we hypothesize lower FNC in OAB patients. METHODS: We examined 10 healthy females (37 9y) and 10 with OAB (38 8y) and DO in urodynamics. For RS-fMRI whole brain images, using a multi-slice EPI sequence were acquired in a 3T scanner. Using SPM8, we estimated the RS NTs using the GIFT toolbox and independent component analysis (ICA) across all subjects. IC dimension estimation was performed using the minimum description length criteria, modified to account for spatial correlation. All nonneuronal ICs (e.g. cardiac-induced pulsatile artifact and head motion) were removed, resulting in a total of 9 neuronal ICs (including the default mode NT, DMN). Prior to FNC analysis, IC time courses were bandpass (0.013 Hz & 0.24 Hz). Group differences in FNC strength were calculated using the FNC toolbox for both conditions. The temporal lags between ICA-derived NTs were computed to gain directed FNC. Significant between-group FNC (and lag) results are shown at p < 0.05 FDR corrected. RESULTS: Healthy controls showed significantly higher (directed) FNC than OAB patients for: DMN (left-dominant) / DMN (right-dominant) and fronto-parietal attention NT / DMN (left-dominant). OAB patients show lower inter-networkcoupling, especially between the DMN(IC1) and the left-dominant fronto-parietal attention NT (FPN,IC4). Further, FNC differed between groups in temporal synchronicity. E.g., lag time between the DMN and FPN is shorter than between the right and left DMN in OAB patients. CONCLUSIONS: We conclude that the interplay between neuronal NTs is altered in OAB patients compared to healthy subjects already during RS. Aberrant coupling of the fronto-parietal attention NT might indicate a general neuronal deficit that impairs adequate LUT control, i.e. suppression of premature micturition reflex, consequently resulting in OAB and incontinence. These novel findings can be an important link to the underlying pathophysiology of OAB in otherwise neurological unimpaired patients.

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